Electro-optic effect of a soluble nonlinear optical polyimide containing two different chromophores with different sizes in the side chain

Abstract

A new soluble and thermally stable nonlinear optical (NLO) polyimide was synthesized by adding both tricyanopyrroline (TCP)-and tricyanofuran (TCF)-based NLO chromophores into the polymer backbone. The NLO polyimide (PI-II) bearing two different chromophores with different sizes has a glass transition temperature of 146 o C and exhibits good film forming properties. The electro-optic coefficient of the film was 84 pm/V at 1.3 µm under a poling field of 80V/µm, even though PI-II has an unusually high chromophore density of approximately 20 wt% of TCP chromophores and 23 wt% of TCF chromophores. Even with a overall chromophore loading of 43 wt%, no severe aggregation effect was observed for the sample that exhibited a relatively high EO coefficient.

Monomer Dependence of Colorless and Transparent Polyimide Films: Thermomechanical Properties, Optical Transparency, and Solubility

“…However, because most polymer main chains consist of a linear structure, they are difficult to dissolve in strong solvents and melt at high temperatures. , Therefore, the application of CPI as a superengineering polymer is very limited despite its excellent chemical properties. When processing a CPI solution into a film, selecting an appropriate solvent to increase the solubility to facilitate the process and improve the quality of the film is very important. , The solubilities of the six synthesized CPI films measured in various solvents are summarized in Table . All CPI films were completely insoluble in general-purpose solvents, such as acetone, chloroform, ethyl alcohol, and methyl alcohol.…”

“…When processing a CPI solution into a film, selecting an appropriate solvent to increase the solubility to facilitate the process and improve the quality of the film is very important. 59 , 60 The solubilities of the six synthesized CPI films measured in various solvents are summarized in Table 4 . All CPI films were completely insoluble in general-purpose solvents, such as acetone, chloroform, ethyl alcohol, and methyl alcohol.…”